In most recent years, Zero Trust model is gaining significant traction in the cybersecurity sphere. The tendency is to migrate from a perimeter-based approach to a perimeter-less one. This trend has been accelerated also by the Covid-19 pandemic which led companies to face the problem of handling the employees connecting from all over the globe. This phenomenon has made the presence of a trusted organisational perimeter useless. The present thesis work aims to analyse, inside a Zero Trust environment, which are the cyber-threats, define potential identity-based attack scenarios, and provide possible countermeasures in line with this model. In the initial part of the thesis most relevant principles of the Zero Trust have been analysed along with a technical description of the cloud platform used to implement it in this work: Azure Active Directory.